serializer/tests/JMS/Serializer/Tests/Metadata/Driver/xml/SimpleClassObject.xml

<?xml version="1.0" encoding="UTF-8"?>
<serializer>
    <class name="JMS\Serializer\Tests\Fixtures\SimpleClassObject">
        <xml-namespace prefix="foo" uri="http://foo.example.org"/>
        <xml-namespace prefix="old_foo" uri="http://old.foo.example.org"/>
        <xml-namespace prefix="new_foo" uri="http://new.foo.example.org"/>
        <property name="foo" type="string" xml-attribute="true">
            <xml-element namespace="http://old.foo.example.org"/>
        </property>
        <property name="bar" type="string">
            <xml-element namespace="http://foo.example.org"/>
        </property>
        <property name="moo" type="string">
            <xml-element namespace="http://new.foo.example.org"/>
        </property>
    </class>
</serializer>